JPH0371591A - High frequency heating apparatus - Google Patents

Abstract

PURPOSE:To shorten heating time without increasing the size of a cooling device by providing a means for inhibiting continuous driving when set time by a time setting means exceeds specific time required for a high frequency generator to reach abnormally high temperature. CONSTITUTION:When key operation of 3 minutes of rapid heating is made on a keyboard 11, a controller 22 identifies whether the set heating time is specific time of 5 minutes or less as regards maximum high frequency output of 800W, and when it identifies that the set time is the specific time or less, a magnetron 5 is continuously driven. On the other hand, if heating time exceeding 5 minutes is set by mistake, the controller 22 identifies that so that heating is not started even if a start key is pressed. With this constitution, the maximum high frequency output can be as large as 800W in a state that the magnetron 5 is continuously driven with rated value of a high voltage capacitor 7 higher than usual without increasing the size of a cooling device 8 for improving cooling ability so that heating time can be shortened.

Description

[Detailed description of the invention] C) Industrial application field The present invention relates to a high frequency heating device such as a microwave oven.

(b) In the conventional microwave oven disclosed in Japanese Patent Application Publication No. 55-50504, etc., the high-frequency generator, which is driven while being cooled by a cooling device, is equipped with a high-voltage transformer having a predetermined rating value and a high-voltage capacitor. It is driven by being supplied with high-voltage power via a power source or the like. In this case, even if the high-frequency generator L is continuously driven for a long time to perform heating at the maximum high-frequency output, the high-frequency generator does not reach an abnormally high temperature because it is cooled by the cooling device.

By the way, the higher the maximum high-frequency output, the better the performance of the microwave oven and the shorter the heating time.In order to increase the maximum high-frequency output in this way, for example, it is better to increase the rated value of the high-voltage capacitor mentioned above. . In this case, if the maximum 5-frequency output is increased in this way, the amount of heat generated by the high-frequency generator and the like increases, so it is necessary to improve the cooling capacity of the cooling device.

However, increasing the cooling capacity requires increasing the size of the cooling device, which increases the cost of the microwave oven.

C) Problems to be Solved by the Invention The present invention aims to provide a high-frequency tJl heating capping device that can shorten the heating time without increasing costs.

(d) Means for Solving the Problems The high-frequency heating device of the present invention includes a heating chamber that accommodates an object to be heated, a cooling device, and a device that supplies high-frequency waves into the heating chamber while being cooled by the cooling device. , a high frequency generator that becomes abnormally high temperature when continuously driven for more than a predetermined time, a drive mode setting means, a time setting means for setting a time related to the drive mode set by the drive mode setting means, and the drive mode setting. When the high frequency generator is set to be driven continuously by the means, if the time set by the time setting means exceeds the predetermined time, the continuous driving is prohibited! L-￥
It consists of steps.

(e) When the working high frequency generator is continuously driven for more than a predetermined period of time,
The reason why such a high-frequency generator reaches an abnormally high temperature even though it is cooled by a cooling device is because, for example, the rated value of a high-voltage capacitor for supplying high-voltage power has been increased. Thus, when the high-frequency generator is continuously driven, the maximum high-frequency output increases and the heating time is shortened.

Furthermore, when the maximum high-frequency output is increased in this way, the amount of heat generated by the high-frequency generator increases, and it is originally necessary to increase the size of the cooling device and improve the cooling performance of the cooling device. However, the cooling performance of the cooling device has not been improved, and therefore, if the high frequency generator is continuously operated for a predetermined period of time, it will reach an abnormally high temperature. However, when the continuous drive mode is set, continuous drive is prohibited if the set time exceeds the predetermined time, and such a cooling device is Even without increasing the size,
]2 The high frequency generator can be prevented from becoming abnormally high temperature,
Does not increase the cost of the semi-f range.

(-) Embodiment Figures 1 and 2 show the structure of a microwave oven according to an embodiment of the present invention.
A heating chamber 3 accommodating the heating chamber 3 and an electrical equipment chamber 4 are formed.

Inside the electrical equipment room 4, there is a high-frequency generator, that is, a magnetron 5, which supplies high-frequency waves for heating the food 2 into the heating chamber 3, and a high-voltage transformer 6 and a high-voltage capacitor for applying high-voltage power to the magnetron. 7, and a cooling device 8 for cooling the magnetron 5, high voltage transformer 6, and high voltage condenser 7. Also, on the front of the microwave oven body l, there is a door 9 that opens and closes the front opening of the heating chamber 3, and is displayed! No. and a keyboard 11 are provided. Referring to FIG. 3, the display 10 has a number display section 12 that displays the heating time and a drive mode display section 13 that displays the drive mode of the magnetron 5. The keyboard 11 has a rapid heating key 14, a 650W key 15, a 430W key I6, 30, which sets the high frequency output.
0W key 17. 150W key 18. 80W key 19,
Number keys 20.20, 0 to 9 to set the heating time.
... and a start key 21 for starting heating.

Rapid heating key 14.650W key 15.450W key 16.30QW key 17.150W key 18% SO
The W key 19 is a drive mode setting means, and the numeric key 2
0.20, . . . are time setting means.

FIG. 4 shows the circuit of the microwave oven. A control section 22 including a microcomputer is provided to control the microwave oven. Based on the setting information from the keyboard 11, the control section It performs display drive control of the display unit 10, and also performs on/off control of the first and second switches 23 and 24. When the first switch 23 is turned on, commercial power is applied to the high voltage transformer 6 via the power fuse 25 and the door switch 26 that is turned on when the door 9 is closed, and based on this, the high voltage transformer 6 is turned on.
High-voltage power is applied to the magnetron 5 via the high-voltage capacitor 7 and the like, and high frequency waves are supplied from the magnetron 5 into the two-legged heating chamber 3 to heat the food 2 at rt.

When the second switch 24 is turned on, the cooling device 8 is connected via the power fuse 25 and the door switch 26.
Commercial power supply power is applied to drive the cooling device 8, and the magnetron 5, high voltage transformer 6, and high voltage capacitor 7 are cooled.

The operation of the microwave oven is controlled by the control section 2.
Figure 5 shows the flow of the operation program incorporated in 2.
This will be explained with reference to FIGS. 6 and 7.

First, when heating the food 2 for 5 minutes in a driving mode with a high frequency output of 450 W as a first step, and then heating the food 2 for 15 minutes in a driving mode with a high frequency output of 300 W as a second step, the keyboard 11 , key operation.

In this case, when the 450W key 16 is operated for the first time, the routine of the operating program shown in FIG. 5 is executed. Such a routine includes 450W key 1 (in addition to i, 650W key 15, 300W key 17.150, W key 18.80)
It is executed even if the W key 19 is operated first.

Then, based on the operation of the =+50W key 16, first, in step At in FIG. 5, a high frequency output of 450W corresponding to the key 16 is set. Then A2, A3, A
The four steps are executed cyclically. In step A2, the heating time is set by operating the number keys 20, 20, . . . on the keyboard 11. In step A3, it is determined whether a key operation has been performed to further set the high frequency output. In A4 step, start key 21
It is determined whether or not the has been operated. Therefore, in such a circular execution, 5, Olo and number keys 20.20,
... is operated, a heating time of 5 minutes related to a high frequency output of 450 W is set in the above step A2: Then, 3
When the 00W key 17 is operated, steps from A3 to A1
Returning to the step, a high frequency output of 300 W is further set, and then steps A2, A3, and A4 are executed again in a circular manner. Then l, 5.0.0 and number keys 20.20,
When ... is operated, the high frequency output is 30 in step A2.
A heating time of 15 minutes for 0W is set.

After such key operations, when the start key 21 is operated to execute heating, the above-mentioned cyclic execution ends at step A1, and then the routine of the operation program shown in FIG. 7 is executed. In this routine, first, in the CI step, the second switch 24 is turned on to start driving the cooling device 8, and the magnetron 5 and the like are cooled. At step R<C2, a countdown of 5 minutes of heating time related to the first high frequency output of 450 to V is started. Subsequently, in step C3, it is determined whether the heating time has reached 0 based on a countdown. If it is not O in this case, then step C4 is executed and it is determined whether the drive mode is 650W or not. In this case, since the driving form is -150W (650W or less), the C5 step is executed thereafter. In this step, the high frequency output 450 which is the current drive form is
According to W, the first swing 23 becomes 3 as shown in FIG. 8C.
The magnetron 5 starts to be turned on for 18.4 seconds at a 0 second period, and based on this, the magnetron 5 is intermittently driven and heating with a high frequency output of 450 W is started. In step C5, if the high frequency output of the current drive mode is 650W, the first switch 23 is turned on for 26 seconds at a cycle of 30 seconds as shown in FIG.
SOW field 1 is as shown in Fig. 8 dSe, f < 12.8
Turn on for seconds, 6.8 seconds, and 4.4 seconds. And 02~C5
Steps are executed cyclically.

Eventually, when the heating time related to the high frequency output becomes O,
Such cyclic execution ends at step 03, step C6 is executed, and it is determined whether the high frequency output is subsequently set. In the present case, a high frequency output of 300 W is subsequently set, and then steps C2 to C5 are executed again in a circular manner. In such recirculation execution, a countdown of 15 minutes of heating time related to the high frequency output of 300 W is started at step C2. In addition, in step C5, the eighth
As shown in FIG. d, the first switch 23 is switched 12.
The magnetron 5 starts to be turned on for 8 seconds, and based on this, the magnetron 5 is intermittently driven, and the high frequency output is 300 W.
heating begins. And this high frequency output 300
When the heating time related to W becomes O, step C6 is executed again, but there is no high frequency output setting after that, so step C7 is executed next. In this step,
The on/off control of the first switch 23 is stopped to terminate heating, and the second switches 2 and 4 are turned off to stop cooling of the magnetron 5 and the like.

In this way, as a first step, a high frequency output of 450W
The food 2 is heated for 5 minutes with the drive mode of
Heating is completed. During such heating, the cooling device 8 is driven to cool the magnetron 5.
etc. are cooled down, and the magnetron 5 etc. do not reach abnormally high temperatures.

Now, if you want to perform rapid heating for 3 minutes, use the above keyboard 1.
At step 1, press the key.

In this case, when the rapid heating key 14 is operated for the first time, the routine of the operating program shown in FIG. 6 is executed. First, in step B1, a maximum high frequency output of 800 to V according to the key 14 is set. Continued <82
In step 1, it is determined whether another high frequency output is set before this maximum high frequency output soow. In this case, there are no other high frequency output settings, then B3, B
4 stenobs are executed in a cycle. In step B3, the heating time is set by operating the number keys 20, 20, . . . . , B4 step, it is determined whether the start key 21 has been operated. Therefore, in such a circular execution, if 3.0.0 and number keys 20.20, . . . are operated successively, the maximum high frequency output so
A heating time of 3 minutes is set for ow.

After such key operations, when the start key 21 is operated to execute heating, the above-mentioned cyclic execution ends in 84 steps, and then step B5 is executed. In this step, it is determined whether the heating time set as described above is less than or equal to the predetermined time of 5 minutes.

In this case, a decision is made within 5 minutes, and then a routine as shown in Figure 7 is executed, and the CI
After the driving of the cooling device 8 is started in step C2,
Steps C3 and C4 are executed. At this time, such C
In step 4, the high frequency output is the maximum soow and is not less than 650W, so after step C4, C
Eight steps are performed. In this C8 step, the 8th
As shown in FIG.
tJrI fever of 0W″C′ starts. Then, from 02 to
Each step of C4 and C8 is executed cyclically.

After that, the prefectural environment actualization ends when the heating time related to the maximum high frequency output becomes 0, and the high frequency output is subsequently executed after the 06 step and the C7 step for the power that has not been set. Continuous ON 11 of first switch 23
The control is stopped, heating is ended, the second switch 24 is turned off, and cooling of the magnetron 5 and the like is stopped.

In this way, 3 minutes of rapid heating is completed.)
During such heating, the cooling device 8 is driven to cool the magnetron 5 and the like, so that the magnetron 5 and the like do not reach abnormally high temperatures.

On the other hand, if the heating time for the maximum high-frequency output of 800 W corresponding to rapid heating is mistakenly set to exceed the predetermined time of 5 minutes, this will be determined at step B5 in FIG. 6, and the start key 21 will be operated. Even if the heating is performed, the routine shown in FIG. 7 is not executed and heating is not started. Incidentally, in such rapid heating, a heating time of 5 minutes is sufficient.

Here, the rated value of the high-voltage capacitor 7 is larger than usual, and as a result, as mentioned above, the magnetron 5
The maximum high frequency output when the is continuously driven is so
OW, which enables rapid heating and shortening of heating time. In this case, the amount of heat generated by the magnetron 5 and the like increases. However, the size of the cooling device 8 has not been increased accordingly, and the cooling performance has not been improved. Although the magnetron 5 and the like are cooled by the cooling device 8, the temperature becomes abnormally high.

In view of this, if the heating time for the maximum high frequency output of 800~V corresponding to rapid heating is mistakenly set to exceed the predetermined time of 5 minutes, as in the case of double series, the heating time shown in Figure 6. Since the start of heating is prohibited based on the judgment in step B5, 1-, the magnetron 5 etc. described above do not need to be enlarged in order to improve the cooling performance of the cooling device 8. Abnormally high temperatures are suppressed. Furthermore, since the cooling device 8 is not made large, the cost of the microwave oven does not increase.

As can be seen from this, step L B5 corresponds to the prohibition means of the present invention.

Furthermore, if you set another high-frequency output before the maximum high-frequency output of 800W and perform heating using the other high-frequency output and heating using the maximum high-frequency output in succession, it will be rejected in step B2 above and will be prohibited +1 second. be done. That is, there is a risk that the magnetron 5 and the like may reach an abnormally high temperature even during such combination heating.

Furthermore, it is also possible to set another high frequency output after the maximum high frequency output of 800 W and perform heating using the maximum high frequency output and heating using the other high frequency output in succession.
After the operation of FIG. 6 is executed, the step that can set the high frequency output of the pond is disabled as well. Of course, this is because there is a risk that the magnetron 5 and the like may become abnormally high temperature.

(G) Effects of the Invention According to the present invention, in improving the maximum high-frequency output during continuous operation of the high-frequency generator, although the amount of heat generated by the high-frequency generator W increases, it is possible to increase the size of the cooling device that cools the high-frequency generator. The present invention provides an extremely practical high-frequency heating device that eliminates the need to improve the cooling performance of the cooling device, thereby shortening the heating time without incurring the increased costs associated with increasing the size of the cooling device. can.

[Brief explanation of drawings]

The drawings relate to a microwave oven according to an embodiment of the present invention, and FIG. 1 is an external perspective view, FIG. 2 is a right side sectional view, and FIG. 3 is a front view of main parts.
FIG. 1 is a circuit diagram, FIGS. 5, 6, and 7 are flowcharts of the operation programs incorporated in the control section, and FIG. 8 is an operation timing diagram of the first switch. 3...Heating chamber, 5...Magnetron, 8...Cooling device, 11...Keyboard, 22...Control unit. Figure 2

Claims (1)

[Claims] (1) A heating chamber that accommodates an object to be heated, a cooling device, and a high frequency wave that is cooled by the cooling device and that generates an abnormally high temperature if the heating chamber is continuously driven for a predetermined period of time. a generator, a drive mode setting means, a time setting means for setting a time related to the drive mode set by the drive mode setting means, and when the drive mode setting means sets the high frequency generator to be continuously driven; and prohibiting means for prohibiting the continuous driving when the time set by the time setting means exceeds the predetermined time.